Glial cells develop a laminar pattern before neuronal cells in the lateral geniculate nucleus.

The lateral geniculate nucleus, which lies between the retina and the striate cortex in the visual pathway of mammals, is often made up of several distinctive cell layers, or laminae. We have used immunohistochemical methods to localize two glial cell intermediate filament proteins, glial fibrillary acidic protein and vimentin, and have found that layering of glial cells is evident before neuronal cell layers develop in the lateral geniculate nucleus. The correlation between glial cell lamination and neuronal lamination is consistent with the suggestion that glia are guiding neurons not only during the early postmitotic migratory phase of development but also during the later formation of functional divisions such as layers and nuclei.